/**
 *
 * @author lty
 */
public class Main {
    public static void main(String[] args) {
        String userLevel = "gold";

        // 使用会员工厂类创建会员对象
        Member member = MemberFactory.createMember(userLevel);
        if (member != null) {
            member.sign();
        } else {
            System.out.println("Invalid member level");
        }
    }
}
